1. Field of the Invention
The present invention relates generally to storage libraries for storing a plurality of media elements such as tape cartridges and, more particularly, to robotic assemblies that are configured to manipulate media elements within a storage library.
2. Relevant Background
Storage library systems are often used by enterprises and the like to efficiently store and retrieve data from storage media. In the case of some storage libraries, the media may be data or media elements (e.g., tape cartridges) that are typically stored and indexed within a set of magazines. When particular data is requested, for instance, a specialized robotic assembly or mechanism (e.g., robotic module) finds the appropriate cartridge, removes the cartridge from its magazine, and carries the cartridge to a drive that is designed to receive the cartridge and read its contents. Some storage libraries have multiple drives that can operate concurrently to perform input/output (IO) operations on multiple cartridges.
To operate properly, each robotic mechanism is expected to reliably (e.g., repeatedly and accurately) and rapidly find, retrieve, and deliver desired media elements (e.g., per instructions from one or more host computers) throughout the storage library cartridge inventory. Generally, a robotic mechanism includes a hand assembly (e.g., including a picker assembly) that is operable to reliably grip a desired cartridge and remove it from a magazine or drive, or to reliably grip a cartridge and release the cartridge into a desired magazine slot or drive. The robotic mechanism is often configured to translate or displace an arm on or in which the hand assembly is mounted along the z axis (e.g., in the vertical dimension along a column of media elements) and along an x or y axis (e.g., in a horizontal dimension along a row of media elements), such as through any appropriate arrangement of gears, tracks, belts, cables, hydraulics, and/or other such control mechanisms. Some robotic mechanisms are configured to pivot or rotate the arm and/or hand assembly about one or more of the x, y, or z axes (e.g., roll, pitch and yaw, respectively).
As automated storage libraries have become larger and more complex, their designs have evolved from a single wall or array of storage slots to multiple walls of storage slots in various shapes and configurations. For instance, one type of storage library includes first and second spaced storage arrays separated by an aisle and whose storage or magazine slots generally face each other. A robotic assembly (e.g., robotics module) mounted over one of the storage arrays is configured to manipulate media elements on the storage array, such as by grabbing and removing a media element and mounting the media element in another storage slot or media drive or by grabbing and inserting a media element into a particular storage slot of the array. In one arrangement, a robotic assembly may be configured to manipulate media elements of either of the first or second spaced storage arrays, such as by pivoting or rotating its robot arm through 180° or the like to access the first or second storage arrays as appropriate. In an attempt to increase throughput, two or more robotic assemblies may be mounted on the same rail assembly over one of the storage arrays, where the robot arms of each of the robotic assemblies can access media elements of both of the first and second storage arrays, such as by pivoting or rotating its robot arm through 180° or the like to access the first or second storage arrays as appropriate.